Recent content by Metal Man

Just as i think i might be starting to understand, things complicate further. :( I think i have somewhat of an idea anyhow, so i will continue with making the cover, and finding the possible mounting locations, calculate what i think i have learned to be close, and probably post up again with...

Picture added...

Ok, still not sleeping. Here is a link to something i have seen in the past that is dealing with a similar principle, and i think it may actually be wrong according to what we have discussed here. http://www.rodandcustommagazine.com/techarticles/0812rc_coilover_spring_rates/ On their...

So for further confirmation and understanding here is another picture with a different lower mount with 9° closed and 40° open. Needed spring force here at closed to make cover weightless is 384, or divide by 2 springs = 192lbs each. Probably not a good plan and puts unneeded stress on the...

Ok, this helps me understand a little better. Using the angle and sin on the calculator to get the figure we need. I did fail to think about the leverage closing it. One more thing to grind my brain with. I am going to have to shut down the thinker here before too long and get ready for...

Ok, another picture with the lengths and dealing with the sin = opposite/hyp or 14.5537/26.9133 = .54 of Axial Spring force. Vertical lift at attachment on cover, cover closed = 0.54 * axial strut force, OR Weight of 60 / .54 = 111.111 lbs needed of spring Force for 60lbs Vertical Force...

The spring lower mount is yet to be determined, just a general area, but could change. I read that if possible they should be kept at 30deg or more at the place the rest the most (closed) to insure that the oil keeps the seal lubricated fully. I have attached another picture with a theoretical...

I think i was over complicating things and getting confused with all the terminology that i am not used to. Thank you for describing it differently. I will look at it again probably after supper and see what i come up with and see how clear things are.

Using that drawing and figuring the reaction force for both opened and closed, i get 60lbs for Rb, with the attachment point on Center of Gravity (center of lid). Not sure if I am doing something wrong or missing something. The sum moments about hinge = 0, I am understanding for this example...

when I said cover weight, I should have said force against the gas spring.

tduell, yes this is all foreign to me. I can build a CNC Plasma/Router/Scribe table from scratch, and make the aluminum cover no problem, but this i need to learn as it is greek to me. Maybe an example, would help. Let's say for ease of example, the weight of the cover is 60lbs, Length is...

Terry, what your saying sounds like a good plan. What are the formulas or methods for figuring out the forces? I have a cad program, that is were that pic was drawn. I think i understand the weight that needs to be lifted, if connected at the CG, Horizontal would be 60lbs, 45deg would be...

Here is a quick drawing, spring is drawn with extended (33.94") and compressed (17.8", stroke is 16.14") lengths for mounting points. Is mounting at CG a must? I figured to make it need less force, i could mount it maybe 1/3 from end, and then mount it somewere close to the blue circle area...

I am working on making an aluminum truck bed cover for a customer despite my attempts to pass it up, he insists that i make it for him. Fabricating it, is not a problem, but I am having a hard time figuring out the force and length of gas springs needed and the best mounting angles for them. I...